Axial compressor configuration

ABSTRACT

An axial compressor includes a housing and a plurality of stages arranged within the housing and along an airflow direction, each stage of the plurality of stages including a first blade assembly and a second blade assembly, wherein the first blade assembly is a rotor, each rotor being drivable independently from the rotors in the other first blade assemblies.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the benefits of U.S. ProvisionalApplication No. 62/113,511 filed on Feb. 8, 2015, and of U.S.Provisional Application No. 62/240,718 filed on Oct. 13, 2015, thedisclosures of which are expressly incorporated by reference herein intheir entireties.

FIELD OF THE DISCLOSURE

The present disclosure relates to an axial compressor and a method foroperating an axial compressor.

BACKGROUND OF THE DISCLOSURE

Traditional transportation modes via water, land, rail and airrevolutionized the movement and growth of our current culture. However,the adverse environmental, societal and economic impacts of thesetraditional transportation models initiated a movement to findalternative transportation modes that take advantage of the significantimprovements in transportation technology and efficiently move peopleand materials between locations. High speed transportation systemsutilizing rails or other structural guidance components have beencontemplated as a solution to existing transportation challenges whileimproving safety, decreasing the environmental impact of traditionaltransportation modes and reducing the overall time commuting betweenmajor metropolitan communities.

One transportation system utilizes a low-pressure environment in orderto reduce drag on a vehicle at high operating speeds, thus providing thedual benefit of allowing greater speed potential and lowering the energycosts associated with overcoming drag forces. These systems are embodiedby a tubular structure in which a near vacuum exists within the tube.

A range of possibilities exist when optimizing a vehicle's design fortravelling inside of a low-pressure tube. At one extreme, the vehiclemay have a frontal cross-sectional area that is much smaller than thatof the tube, e.g., akin to a needle moving inside of a large tube. Thevehicle is relatively small and the tube wall provides very littleinfluence on the vehicle. The working fluid in the tube, such as air, isfree to move around the needle with little restriction or pressurebuild-up in front of the needle.

At the other extreme, the vehicle's frontal cross-sectional area isapproximately the same size as the tube, e.g. a piston moving inside ofa large tube with very small wall clearance (known as the “syringeeffect”). With such a configuration, it is difficult for the workingfluid to move around the vehicle, and pressure will build up in front ofthe vehicle, which greatly increases the drag force on the vehicle inthe tube.

The tradeoff between these two extremes is either building an enormous,expensive tubular structure to avoid significant flow choking on thevehicle, or using a tight-fitting, material-efficient tubular structurethat necessitates a significant drag penalty which must be overcome bythe vehicle. It is thus desirable to achieve the best of both worlds,such as a tube that is only slightly larger than the vehicle, but withvery low drag.

Turbofan or turbojet engines utilize a diffuser prior to the air inletto slow the high speed flow to lead to more efficient compression;however, this technique works better in a free-stream condition wherethe flow that is not taken into the engine intake is easily passedaround the vehicle nacelle. When a vehicle is travelling at high speedthrough an enclosed environment, the flow that is passed around thevehicle nacelle can choke in the space between the nacelle cover and thetube wall. Essentially, the flow inside the nacelle decelerates whilethe flow outside accelerates.

Axial compressors typically include rotating and stationary components.A shaft drives a central drum, retained by bearings, which has a numberof annular airfoil rows attached usually in pairs, one rotating and onestationary attached to a stationary tubular casing. A pair of rotatingand stationary airfoils is called a stage. The rotating airfoils, alsoknown as blades or rotors, accelerate the working fluid. The stationaryairfoils, also known as stators or vanes, convert the increasedrotational kinetic energy into static pressure through diffusion andredirect the flow direction of the fluid, preparing it for the rotorblades of the next stage. The cross-sectional area between rotor drumand casing is reduced in the flow direction in an effort to maintain anoptimum Mach number using variable geometry as the fluid is compressed.

An issue that can face compressors operating in a tubular structure, inparticular axial compressors driven by a common driveshaft, is that theycan suffer loss of performance and/or catastrophic failure due to stall.Stall is primarily caused by flow separating from compressor blades.Flow separation is in large part caused by flow hitting the blades at asub-optimal angle of attack or in regions with adverse pressuregradients. Flow separation is exacerbated further by high Mach numberscaused by local flow accelerating to supersonic speeds and causing shockwaves on the blades; and low Reynolds numbers caused by laminar flowthat is more prone to separation. At high Reynolds numbers, turbulencesometimes helps re-attaching a separated flow back onto the blade.

Further, axial compressors can suffer performance losses due to shockwaves. Shock waves can be the result of high local Mach numbers. Therelative velocities and Mach numbers are higher near the tips of bladeswhere the tangential component of the velocity vector is highest due tothe larger radiuses/diameters.

SUMMARY OF THE DISCLOSURE

An axial compressor includes a housing and a plurality of stagesarranged within the housing and along an airflow direction, each stageof the plurality of stages comprising a first blade assembly and asecond blade assembly, wherein the first blade assembly is a rotor, eachrotor in each first blade assembly being drivable independently from therotors in the other first blade assemblies.

Also included may be an electric motor attached to each rotor. A centralshaft about which the rotors rotate may be provided, wherein eachelectric motor is mounted to the central shaft. Each electric motor maybe mounted to an inside of the housing.

A sensor configured to detect an airflow condition may be provided,wherein each rotor is independently drivable in accordance with thedetected airflow condition.

The second blade assembly may be a counter-rotating rotor configured torotate in an opposite rotational direction of the rotors, eachcounter-rotating rotor being drivable independently from the othercounter-rotating rotor and rotors. Also, an electric motor may beattached to each rotor and counter-rotating rotor. A central shaft aboutwhich the rotors and counter-rotating rotors rotate may be provided,wherein each electric motor is mounted to the central shaft. Eachelectric motor may be mounted to an inside of the housing.

A sensor configured to detect an airflow condition may be provided,wherein each rotor and counter-rotating rotor is independently drivablein accordance with the detected airflow condition.

A vehicle may be provided, the front end to which the compressor ismounted. Also provided may be a tube through which the vehicle isconfigured to travel.

An aspect of the disclosure provides an axial compressor includes ahousing and a plurality of stages arranged within the housing and alongan airflow direction, each stage of the plurality of stages comprising arotor and a counter-rotating rotor, each counter-rotating rotor beingdriveable independently from the counter-rotating rotors in the otherstages. A vehicle may be provided, the front end to which the compressoris mounted. Also provided may be a tube through which the vehicle isconfigured to travel.

Another aspect of the disclosure provides method for operating an axialcompressor having a plurality of stages arranged within a compressorhousing and along an airflow direction, each stage of the plurality ofstages having a first blade assembly and a second blade assembly, themethod including detecting, via a sensor, an airflow condition of theaxial compressor, and driving, via an electric motor, at least one ofthe first blade assemblies and second blade assemblies independently, inaccordance with the detected airflow condition.

The compressor may be mounted to a front end of a vehicle, and thevehicle may be operated to travel within a tube.

A further aspect provides an axial compressor system including a centralaxial compressor, and a first plurality of axial compressors arrangedabout a longitudinal axis of the central axial compressor. The firstplurality of axial compressors may be arranged downstream of the centralaxial compressor.

A second plurality of axial compressors arranged about the firstplurality of axial compressors may be provided. The second plurality ofaxial compressors may be arranged downstream of the first plurality ofaxial compressors. The second plurality of axial compressors may bestaggered in the circumferential direction with respect to the firstplurality of axial compressors. Each axial compressor of the firstplurality of axial compressors and central axial compressor may bedrivable independently from the other axial compressors.

A vehicle may be provided, the front end to which the compressor ismounted. Also provided may be a tube through which the vehicle isconfigured to travel.

Yet another aspect of the disclosure provides a transportation systemhaving a vehicle configured to travel through at least one tube betweenstations, the vehicle including a first compressor having a firstdiameter which narrows in a direction of air flow, the first compressorincluding a first intake configured to ingest gas, and a first exhaustconfigured to expel compressed gas. Further included is a secondcompressor coaxial with and positioned downstream from the firstcompressor and having a second diameter greater than the first diameter,the second compressor having a central aperture in communication withthe exhaust of the first compressor, a ring-shaped intake surroundingthe central aperture and configured to ingest gas uncompressed by thefirst compressor, and an exhaust configured to expel gas compressed bythe first and second compressors.

Yet a further aspect of the disclosure provides a transportation systemcomprising a vehicle configured to travel through at least one tubebetween stations, the vehicle having a first compressor having a firstdiameter and including a first intake configured to ingest and compressgas, a central aperture surrounded by the intake, and a first exhaustconfigured to expel the compressed gas, and a second compressor coaxialwith and positioned downstream from the first compressor and having asecond diameter that is smaller than the first diameter and thatincreases in the direction of airflow. The second compressor has asecond intake configured to ingest gas passed through the centralaperture uncompressed by the first compressor, and a second exhaustconfigured to expel gas, wherein gas expelled by the first and secondexhausts are combined.

Other exemplary embodiments and advantages of the present disclosure maybe ascertained by reviewing the present disclosure and the accompanyingdrawings, and the above description should not be considered to limitthe scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features which are characteristic of the systems, both as tostructure and method of operation thereof, together with further objectsand advantages thereof, will be understood from the followingdescription, considered in connection with the accompanying drawings, inwhich a presently preferred embodiment of the system is illustrated byway of example. It is to be expressly understood, however, that thedrawings are for the purpose of illustration and description only, andthey are not intended as a definition of the limits of the system. For amore complete understanding of the disclosure, as well as other aims andfurther features thereof, reference may be had to the following detaileddescription of the disclosure in conjunction with the followingexemplary and non-limiting drawings wherein:

FIG. 1 shows a schematic view of the transportation system according toan aspect of the disclosure;

FIG. 2 shows a view of an exemplary capsule for use in thetransportation system in accordance with an aspect of the disclosure;

FIG. 3 shows a sectional perspective schematic view of a compressoraccording to an aspect of the disclosure;

FIG. 4 shows a sectional perspective schematic view of a compressoraccording to an aspect of the disclosure;

FIG. 5 shows a side sectional schematic view of a compressor accordingto an aspect of the disclosure;

FIG. 6 shows a side sectional schematic view of a compressor accordingto an aspect of the disclosure;

FIG. 7 shows a schematic diagram of influences upon the compressoraccording to an aspect of the disclosure;

FIG. 8 shows a front plan schematic view of a compressor systemaccording to an aspect of the disclosure;

FIG. 9 shows a front plan schematic view of a compressor systemaccording to an aspect of the disclosure;

FIG. 10 shows a schematic perspective view of a compressor systemaccording to an aspect of the disclosure;

FIG. 11 shows a front plan schematic view of a compressor systemaccording to an aspect of the disclosure;

FIG. 12 shows a side schematic view of a compressor system according toan aspect of the disclosure;

FIG. 13 shows a perspective view of a serial compressor system accordingto an aspect of the disclosure;

FIG. 14 shows a sectional perspective view of the serial compressorsystem of FIG. 13;

FIG. 15 shows a sectional perspective view of a serial compressor systemaccording to a further aspect of the disclosure;

FIG. 16 shows a sectional perspective view of the serial compressorsystem of FIG. 15; and

FIG. 17 is an exemplary system for use in accordance with theembodiments described herein.

DETAILED DESCRIPTION

In the following description, the various embodiments of the presentdisclosure will be described with respect to the enclosed drawings. Asrequired, detailed embodiments of the present disclosure are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention that may be embodied in variousand alternative forms. The figures are not necessarily to scale; somefeatures may be exaggerated or minimized to show details of particularcomponents. Therefore, specific structural and functional detailsdisclosed herein are not to be interpreted as limiting, but merely as arepresentative basis for teaching one skilled in the art to variouslyemploy the present disclosure.

The particulars shown herein are by way of example and for purposes ofillustrative discussion of the embodiments of the present disclosureonly and are presented in the cause of providing what is believed to bethe most useful and readily understood description of the principles andconceptual aspects of the present disclosure. In this regard, no attemptis made to show structural details of the present disclosure in moredetail than is necessary for the fundamental understanding of thepresent disclosure, the description is taken with the drawings makingapparent to those skilled in the art how the forms of the presentdisclosure may be embodied in practice.

As used herein, the singular forms “a,” “an,” and “the” include theplural reference unless the context clearly dictates otherwise. Forexample, reference to “a magnetic material” would also mean thatmixtures of one or more magnetic materials can be present unlessspecifically excluded.

Except where otherwise indicated, all numbers expressing quantities usedin the specification and claims are to be understood as being modifiedin all instances by the term “about.” Accordingly, unless indicated tothe contrary, the numerical parameters set forth in the specificationand claims are approximations that may vary depending upon the desiredproperties sought to be obtained by the present invention. At the veryleast, and not to be considered as an attempt to limit the applicationof the doctrine of equivalents to the scope of the claims, eachnumerical parameter should be construed in light of the number ofsignificant digits and ordinary rounding conventions.

Additionally, the recitation of numerical ranges within thisspecification is considered to be a disclosure of all numerical valuesand ranges within that range. For example, if a range is from about 1 toabout 50, it is deemed to include, for example, 1, 7, 34, 46.1, 23.7, orany other value or range within the range.

The various embodiments disclosed herein can be used separately and invarious combinations unless specifically stated to the contrary.

Transportation System Overview

Referring to FIG. 1, a transportation system 10 in accordance with thepresent disclosure is illustrated. Transportation system 10 includes oneor more capsules or transport pods 12 traveling through at least onetube 14 between one or more stations 16. In one exemplary embodiment ofthe present disclosure, the one or more capsules of the transportationsystem move through a low pressure environment within the at least onetube 14. In accordance with aspects of the disclosure, a low pressureenvironment includes any pressure that is below 1 atmosphere (orapproximately 1 bar) at sea level.

Some elements of a high-speed transportation system are discussed incommonly-assigned U.S. application Ser. No. 15/007,783, entitled“Transportation System,” filed on even date herewith, the entirecontents of which are expressly incorporated by reference herein.

In one feature of the present disclosure, a system includes apartially-evacuated cylindrical tube that connects the stations in aclosed loop system. Tubes are sized for optimal air flow around thecapsule to improve performance and energy consumption efficiency at thetravel speed. This low pressure environment minimizes the drag force onthe capsule while maintaining the relative ease of pumping out the airfrom the tube.

In embodiments, the capsule may be levitated using a pressurized fluidflow (e.g., air) exiting out, e.g., a bottom side of the capsule andinteracting with a corresponding track. While embodiments of the presentdisclosure are directed to using a low pressure environment, in somecontemplated embodiments, the environment may be at atmospheric pressure(i.e., not a low pressure environment), which may be easier to maintainas compared to a low pressure environment. For example, with someshorter travel distances (for example, short enough that the capsule maynot easily attain a high speed before needing to slow down again), itmay be more efficient to run the system in an environment that is atatmospheric pressure to, for example, reduce costs of maintaining a lowpressure environment. For example, if a route was only 30 km long, thepod will not be able to achieve its top speed (due to relatively shortdistance of the route). In such embodiments, the disclosure contemplatesthat it may be unnecessary to reduce the operating pressure of theenvironment below atmospheric pressure.

In accordance with aspects of the disclosure, in embodiments, thepressure of the environment may be, by design, operating at a uniformpressure (e.g., a uniform low pressure). The inventors contemplate,however, that embodiments of the disclosure may include differentregions that are operating at different pressures (e.g., two differentlow pressures).

In accordance with aspects of the disclosure, the capsules, sections ofthe tube, and the track are able to communicate with each other so asto, for example, control a capsule traveling within the tube and/orcontrol operating conditions of the tube or track. For example, spacingbetween capsules within the same tube may be maintained using autonomousvehicles that are aware of the other capsules' relative location.Additional aspects, embodiments and details of a high-speedtransportation system are discussed in commonly-assigned U.S.application Ser. No. 15/007,718, entitled “DEPLOYABLE DECELERATOR,”filed on even date herewith, the entire contents of which are expresslyincorporated by reference herein. For example, if a vehicle ahead on thetube path has slowed (e.g., due to a malfunction), then the othercapsules upstream of the slowed capsule may recognize the situation, andmay slow the velocity of the upstream capsules. As a further example ofcommunication between elements of the system in order to controloperating conditions, during a seismic event, portions of a tube thatdetect the seismic activity (e.g., are closer in proximity to theepicenter of the seismic activity), may communicate with portions of thetube further from the epicenter to adjust operating conditions of thetube (e.g., thermal expansion joints, or vibration dampening elements)to account for the seismic activity.

In embodiments, should there be a loss of communication between capsulesthemselves, the capsules and the track or tube, the system will shutdown the system, and for example, let air pressure into the tube so asto assist in deceleration of the capsules. That is, by removing orreducing the low pressure environment in the tube (e.g., bringing thepressure to atmospheric pressure), the capsules will encounter greaterair resistance, which causes the capsules to slow down.

Referring now to FIG. 2, an exemplary and non-limiting depiction of acapsule or transport pod 12 of the transportation system is illustrated.In embodiments, the capsule 12 may be streamlined to reduce an air dragcoefficient as the capsule 12 travels through the low-pressureenvironment of the at least one tube 14 of the transportation system. Inaccordance with aspects of the disclosure, in embodiments, a compressor20 arranged proximate or at the front end of the capsule is operable toingest at least a portion of the incoming air (instead of displacing theair around the vehicle). For example, as schematically shown in theexemplary embodiment of FIG. 2, in embodiments, the capsule 12 mayinclude the compressor 20 at its leading face. In embodiments, thecompressor 20 may include a diffuser, and is operable to ingest oncomingair and utilize the compressed air for the levitation process (when, forexample, the capsules are supported via air bearings that operate usinga compressed air reservoir and aerodynamic lift). Additionally, asschematically shown in the exemplary embodiment of FIG. 2, inembodiments, the compressed air may be used to spin a turbine, forexample, located at the rear end of the capsule, to provide power to thecapsule 12.

Compressor Configuration

As shown in FIG. 2, the capsule (also called a “vehicle”) 12 includesone or more onboard compressors 20. In accordance with aspects of thedisclosure, the compressor 20 allows the capsule to traverse therelatively narrow tube 14 without impeding air flow that travels betweenthe capsule and the walls of the tube. For example, operation of thecapsule 12 through the tube 14 may result in a build-up of air mass infront of the capsule 12, which may increase the drag coefficient. Thecompressor 20 is operable to compress air that is bypassed through thecapsule 12. That is, instead of the oncoming air being passed around thecapsule 12, in embodiments, the compressor 20 is operable to ingest atleast a portion of the oncoming air, so as to reduce drag on the capsule12. In exemplary and non-limiting embodiments, the compressor ratio ofthe compressor may be 30/1, may be 4/1, or may be somewhere within thisrange, depending on the requirements of a particular application. It isalso noted that while the vehicle 12 described herein refers to a podtraveling through a tube, it is contemplated that the compressor 20 andcompressor system 200 can be used in other applications, including butnot limited to stationary or mobile household, commercial or industrialapplications, aircraft, hovercraft, trains and the like.

In embodiments, the compressor 20 may also supply air to, e.g., a bottomside of the capsule 12 to air bearings, which provide a cushion of airto support the weight of the capsule throughout the journey.

Referring to FIG. 3, the compressor 20 is housed within a housing 22,and includes a plurality of stages 24 longitudinally arranged in thedirection of airflow A. In embodiments, ten to twenty stages 24 are usedin the compressor 20; however, those skilled in the art will appreciatethat fewer than ten or greater than twenty stages may be employed inalternative embodiments, depending on the requirements of theapplication. Each stage includes a rotor 26 and a stator 28 which serveto compress and pass a working fluid (e.g., air or other gas) out anexhaust 30. In embodiments, the diameter of the housing 22 is reduced inthe direction of airflow A in order to assist in the compression of theworking fluid. In such embodiments, each stage 24 (and the rotor 26 andstator 28 therein) also have diameters that are reduced in the directionof airflow A.

A feature of the disclosure provides independent stage control to createan efficient compression system which dramatically increases the speedof the vehicle with little drag penalty and decreases tube size. Thestages 24 do not need to have a shaft, although in some embodiments itcan, and each stage can be driven independently. In this regard, eachrotor 26 is independently driven by a motor 32 a, 32 b. In other wordseach rotor 26 can be operated at a rotational speed independent of therotational speeds of the other rotors. Each rotor may be driven by itsown motor 32 a, 32 b, or may be driven by a single motor via, e.g., areduction gear system. Driving the rotors 26 independently allows thecompressor 20 to bypass flow around the payload with some thrustgeneration, which is a significantly different type of engine than whatis presently embodied by known turbo-fan or jet engines. Further, it isappreciated by those skilled in the art that the motors 32 a, 32 b maybe electric or may be powered by another power source, depending on therequirements of the particular application.

As shown in FIG. 5, sensors 3810 and/or feedback control mechanisms(described below) monitor conditions related to the compressor 20 (suchas airflow in and around the compressor), and the system 3800 canreceive this information and (where necessary) adjust and re-adjust therotational speed of each rotor 26 when a predetermined threshold orcondition is reached, such as the detection of flow separation, stalland/or shocks, by communicating with and instructing each motor 32 a, 32b as necessary. It is noted that motors 32 a, 32 b of each stage and/orof the entire system may be in communication with each other over thesystem 3800, via computer(s) 3820 (See also FIG. 17). While FIG. 5 showsa single sensor 3810 inside the housing, it is understood by thoseskilled in the art that multiple sensors may be used inside and/oroutside the housing, depending on the application. Further, thesensor(s) 3810 of FIG. 5 and described herein can be used in connectionwith any embodiments of the invention disclosed herein. It is furthernoted that the sensor(s) 3810 may include an optical sensor, Hall effectsensor, a combination of these two sensors, or any other type ofsuitable sensor.

The disclosure also provides for fine control of the angle of attack andrelative velocity of the flow hitting the blades to eliminate ormitigate flow separation and subsequent stall. In another feature of thedisclosure, as shown in FIG. 4, each stage 24 includes a rotor 26 and acounter-rotating rotor 28′ (rather than a stator), which rotates in arotational direction opposite that of the rotational direction of therotor. Similar to the rotors 26, each counter-rotating rotor 28′ may bedriven by an electric motor, which can be its own motor 32 a, 32 b(independent of the motor used to drive the rotor), or may be driven bya single motor via, e.g., a reduction gear system, or may be driven by amotor common to each stage (such that the common stage motor drives therotor 26 and counter-rotating rotor 28′).

Utilizing counter-rotating rotors allows the system 3800 to control theangle of attack of the flow hitting the blades of the counter-rotatingrotor by varying the RPM (revolutions per minute) of thecounter-rotation, instead of relying on a complicated system ofactuators changing the mounting angle of stator blades. It is noted thatin accordance with a feature of the disclosure, the counter-rotatingrotors 28′ may be driven independently of each other, while the rotors26 are driven together, and that the rotors 26 may be drivenindependently of each other, while the counter-rotating rotors 28′ aredriven together. Still further, the rotors 26 may be driven together ina rotational direction, while the counter-rotating rotors 28′ are driventogether in a rotational direction opposite the rotational direction ofthe rotors.

FIG. 7 shows a schematic diagram of the various influences upon thecompressor. More specifically, reference 2601 shows a rotor blade of afirst stage rotor 26, reference 2602 shows a rotor blade of a secondstage rotor, reference 2603 shows a rotor blade of a third stage rotor.Similarly, reference 2801 shows a rotor blade of a first stagecounter-rotating rotor 28′, and reference 2802 shows a rotor blade of asecond stage counter-rotating rotor 28′. Directional arrow Av representsthe absolute velocity of the blade immediately behind it, directionalarrow Tv represents the tangential velocity of the blade immediatelybehind it, and directional arrow Rv represents the relative velocity ofthe blade immediately behind it. AL represents the aerodynamic limit ofthe blade immediately behind it.

It is further noted that the system 3800 can utilize the above-describedsensors 3810 and feedback control mechanisms to adjust and re-adjust therotational speed of each rotor 26 and counter-rotating rotor 28′ whenthe predetermined threshold or condition is reached.

It is additionally noted that the motor 32 a for each rotor 26 and/orcounter-rotating rotor 28′ may be mounted inside the hub of each rotor,as shown in FIG. 5. The motors 32 b may alternatively or additionally bemounted to the inside of the housing 22, as shown in FIG. 6, or themotors 32 a, 32 b may be mounted to the outside of the housing 22,mounted to a shaft about which the rotors 26, 28′ rotate, or elsewhereby using e.g., shafts, gears, belts, or other modes of transmittingpower to the rotors 26 and/or counter-rotating rotors 28′. The mountingof the motors 32 a, 32 b may also include a magnetic bearing mechanismsimultaneously, and/or air bearings (wherein air is supplied by, e.g.the compressor 20) in order to bypass the need for conventionalmechanical bearings.

It is also noted that the compressor may provide torque to a shaft,including but not limited to reciprocating engines, rotary engines,generators, internal combustion engines, turbines 13 including gasturbines, flywheels, compressed gas engines, and hydraulic motors.

FIGS. 8-14 show varying aspects of a compressor system 200 made of aplurality of smaller diameter compressors which fit within the vehicle12, rather than a single, larger-diameter compressor 20. Use of using aplurality of smaller compressors allows the compressors to spin athigher RPM without the risk of producing supersonic speeds near theirtips. Further, in the event of failure of one or more compressors in thesystem, the remaining operational compressors can still carry out theirintended function (e.g., propelling the vehicle 12) and may evencompensate for the loss of a compressor.

FIG. 8 shows a compressor system 200 having a central compressor 280,surrounded by a ring of six surrounding compressors 282, although it isunderstood by those skilled in the art that more or fewer surroundingcompressors 282 may be used, depending on the application. FIG. 9 showsa compressor system 200 having a central compressor 290, surrounded by afirst ring of surrounding compressors 292, which are in turn surroundedby a second ring of surrounding compressors 294, although it isunderstood by those skilled in the art that more or fewer surroundingcompressors 292, 294 than shown in FIG. 9 may be used. Further, it isnoted that while each compressor 280, 282, 290, 292, 294 is arrangedalong a plane orthogonal to the airflow direction A, it is understood bythose skilled in the art that the compressors 280, 282 may be arrangedalong different planes.

In this regard, FIGS. 10-12 show a compressor system with staggeredcompressors 210, 212, 214 arranged along different planes. The firstcentral compressor 210 is surrounded by a first ring of surroundingcompressors 212 which are downstream in the airflow direction A from thefirst central compressor. A second ring of surrounding compressors 214surrounds and is downstream from the first ring of surroundingcompressors 212. It is also understood by those skilled in the art thatmore or fewer surrounding compressors 212, 214 than shown may be used.When using compressors 210, 212, 214 which have a housing tapereddownstream of the airflow direction A (as shown in FIGS. 10-12), thecompressors may be arranged more tightly together (best seen in FIG.11), thereby minimizing “dead” surface area, or compressor gaps, alongthe face of the vehicle 12. It is further also understood by thoseskilled in the art that that each compressor of the compressor system200 is independently controllable.

FIGS. 13-14 shows a serial compressor system 300 in a further feature ofthe disclosure. A first central compressor 310 has a housing 22 havingdiameter which narrows, or tapers, in a direction of air flow A. Thefirst central compressor 310 is configured to compress high speed flowat a reduced size and mass than that of the full diameter of the tube14. The first central compressor 310 compresses the working fluid (e.g.air), enough to decrease the diameter of the flow, which allows theairflow about the exterior of the housing to decelerate. A secondcompressor 312 is coaxial with and positioned downstream from the firstcompressor, has a housing 22 diameter greater than that of the firstcentral compressor, and narrows in the direction of air flow. The secondcompressor 312 has a central aperture 313 a in communication with theexhaust of the first central compressor 310 such that the exhaust fromthe first central compressor 310 is fed into this central aperture, butis not compressed by the second compressor. The second compressor 312includes a ring-shaped intake 313 b surrounding the central aperture 313a and configured to ingest air uncompressed by the first centralcompressor 310. The exhaust from the second compressor 312 may combinewith the exhaust from the first central compressor 310 and is furtherpassed downstream to a third compressor 314 which is similarlyconfigured to the second compressor 312, but has a larger housingdiameter.

The remaining downstream serial compressors 316, 318, 320 and 322 aresimilarly configured as the upstream compressors 310, 312, 314 eachsuccessively having a larger housing diameter. The final compressor 322is similarly configured to the upstream compressors 310, 312, 314, 316,318, 320, but may have a housing that is generally parallel to the tube14. While FIGS. 13-14 show seven compressors, it is appreciated by thoseskilled in the art that more or fewer compressors may be used, dependingon the requirements of the particular application. For example, serialcompressors may be repeatedly provided until the desired pressure ratiois achieved. Each subsequent serial compressor has a substantiallydecreasing inlet Mach number. The internal flow passages of eachcompressor are initially substantially separate, but may be combineddownstream and flow out in a single passage.

FIGS. 15-16 shows a serial compressor system 400 in a further feature ofthe disclosure, which differs from the system of FIGS. 13-14 primarilyin that the different stages of the compressor are serially stacked fromthe outside inwardly. A first ring-like compressor 410 has a centralaperture 411 a through which incoming air to subsequent compressors 412,414, 416, 418, 420 is passed, and has an inlet 411 b configured toreceive and compress as exhaust a working fluid (e.g., air). The firstcompressor 410 also has a housing 22 that is generally parallel to thetube 14 and contiguous with the exterior of the vehicle 12. A secondring-like compressor 412 is coaxial with and positioned downstream fromthe first compressor, has a housing 22 diameter that is smaller thanthat of the first compressor 410, and is flared in the direction of airflow A. The second compressor 412 has a central aperture 413 a throughwhich incoming air to subsequent compressors 414, 416, 418, 420 ispassed. The exhaust air compressed by inlet 413 b of the secondcompressor is combined with the exhaust air compressed by the firstcompressor 410.

Remaining downstream serial compressors 414, 416, 418 are similarlyconfigured as the compressors 410, 412 upstream from them, eachsuccessively having a flared, smaller housing diameter. The finalcompressor 420 is not a ring-like compressor but rather is similar tothe compressors 20 described with reference to FIGS. 3-6, and has aflared housing that is the smallest of the upstream compressors indiameter. While FIGS. 15-16 show six compressors, it is appreciated bythose skilled in the art that more or fewer compressors may be used,depending on the requirements of the particular application. Forexample, serial compressors may be repeatedly provided until the desiredpressure ratio is achieved. The diffusing action after each serialcompressor slows the flow and increases the static pressure prior toentering each new stage. Each compressor may be independent and drivenfrom motors on the outer wall. The flow after each stage recombines andmoves down stream. The final compressor 420 is provided at a reducedMach number inlet.

It is also understood by those skilled in the art that the compressorsystems 200, 300, 400 can be used with any of the aforementionedfeatures and embodiments described in relation to, e.g., FIGS. 1-7 and17.

System Environment

As will be appreciated by one skilled in the art, aspects of the presentdisclosure may be embodied as a system, a method or a computer programproduct. Accordingly, embodiments of the present disclosure may take theform of an entirely hardware embodiment, an entirely software (excludingthe transducers and A/D converters) embodiment (including firmware,resident software, micro-code, etc.) or an embodiment combining softwareand hardware aspects that may all generally be referred to herein as a“circuit,” “module” or “system.” Furthermore, aspects of the presentdisclosure may take the form of a computer program product embodied inany tangible medium of expression having computer-usable program codeembodied in the medium.

Any combination of one or more computer usable or computer readablemedium(s) may be utilized. The computer-usable or computer-readablemedium may be, for example but not limited to, an electronic, magnetic,optical, electromagnetic, infrared, or semiconductor system, apparatus,device, or propagation medium. More specific examples (a non-exhaustivelist) of the computer-readable medium would include the following:

-   -   an electrical connection having one or more wires,    -   a portable computer diskette,    -   a hard disk,    -   a random access memory (RAM),    -   a read-only memory (ROM),    -   an erasable programmable read-only memory (EPROM or Flash        memory),    -   an optical fiber,    -   a portable compact disc read-only memory (CDROM),    -   an optical storage device,    -   a transmission media such as those supporting the Internet or an        intranet,    -   a magnetic storage device    -   a USB key,    -   a certificate,    -   a perforated card, and/or    -   a mobile phone.

In the context of this document, a computer-usable or computer-readablemedium may be any medium that can contain, store, communicate,propagate, or transport the program for use by or in connection with theinstruction execution system, apparatus, or device. The computer-usablemedium may include a propagated data signal with the computer-usableprogram code embodied therewith, either in baseband or as part of acarrier wave. The computer usable program code may be transmitted usingany appropriate medium, including but not limited to wireless, wireline,optical fiber cable, RF, etc.

Computer program code for carrying out operations of the presentdisclosure may be written in any combination of one or more programminglanguages, including an object oriented programming language such asJava, Smalltalk, C++ or the like and conventional procedural programminglanguages, such as the “C” programming language or similar programminglanguages. The program code may execute entirely on the user's computer,partly on the user's computer, as a stand-alone software package, partlyon the user's computer and partly on a remote computer or entirely onthe remote computer or server. In the latter scenario, the remotecomputer may be connected to the user's computer through any type ofnetwork. This may include, for example, a local area network (LAN) or awide area network (WAN), or the connection may be made to an externalcomputer (for example, through the Internet using an Internet ServiceProvider). Additionally, in embodiments, the present disclosure may beembodied in a field programmable gate array (FPGA).

FIG. 17 is an exemplary system for use in accordance with theembodiments described herein. The system 3800 is generally shown and mayinclude a computer system 3802, which is generally indicated. Thecomputer system 3802 may operate as a standalone device or may beconnected to other systems or peripheral devices. For example, thecomputer system 3802 may include, or be included within, any one or morecomputers, servers, systems, communication networks or cloudenvironment.

The computer system 3802 may operate in the capacity of a server in anetwork environment, or in the capacity of a client user computer in thenetwork environment. The computer system 3802, or portions thereof, maybe implemented as, or incorporated into, various devices, such as apersonal computer, a tablet computer, a set-top box, a personal digitalassistant, a mobile device, a palmtop computer, a laptop computer, adesktop computer, a communications device, a wireless telephone, apersonal trusted device, a web appliance, or any other machine capableof executing a set of instructions (sequential or otherwise) thatspecify actions to be taken by that device. Further, while a singlecomputer system 3802 is illustrated, additional embodiments may includeany collection of systems or sub-systems that individually or jointlyexecute instructions or perform functions.

As illustrated in FIG. 38, the computer system 3802 may include at leastone processor 3804, such as, for example, a central processing unit, agraphics processing unit, or both. The computer system 3802 may alsoinclude a computer memory 3806. The computer memory 3806 may include astatic memory, a dynamic memory, or both. The computer memory 3806 mayadditionally or alternatively include a hard disk, random access memory,a cache, or any combination thereof. Of course, those skilled in the artappreciate that the computer memory 3806 may comprise any combination ofknown memories or a single storage.

As shown in FIG. 38, the computer system 3802 may include a computerdisplay 3808, such as a liquid crystal display, an organic lightemitting diode, a flat panel display, a solid state display, a cathoderay tube, a plasma display, or any other known display. The computersystem 102 may include at least one computer input device 3810, such asa keyboard, a remote control device having a wireless keypad, a sensor,a microphone coupled to a speech recognition engine, a camera such as avideo camera or still camera, a cursor control device, or anycombination thereof. Those skilled in the art appreciate that variousembodiments of the computer system 3802 may include multiple inputdevices 3810. Moreover, those skilled in the art further appreciate thatthe above-listed, exemplary input devices 3810 are not meant to beexhaustive and that the computer system 3802 may include any additional,or alternative, input devices 3810.

The computer system 3802 may also include a medium reader 112 and anetwork interface 114. Furthermore, the computer system 102 may includeany additional devices, components, parts, peripherals, hardware,software or any combination thereof which are commonly known andunderstood as being included with or within a computer system, such as,but not limited to, an output device 116. The output device 116 may be,but is not limited to, a speaker, an audio out, a video out, a remotecontrol output, or any combination thereof.

Aspects of embodiments of the present disclosure (e.g., control systemsfor the tube environment, capsule control systems, tube orientation,tube switching systems) can be implemented by special purposehardware-based systems that perform the specified functions or acts, orcombinations of special purpose hardware and computer instructionsand/or software, as described above. The control systems may beimplemented and executed from either a server, in a client serverrelationship, or they may run on a user workstation with operativeinformation conveyed to the user workstation. In an embodiment, thesoftware elements include firmware, resident software, microcode, etc.

Furthermore, the aspects of the disclosure may take the form of acomputer program product accessible from a computer-usable orcomputer-readable medium providing program code for use by or inconnection with a computer or any instruction execution system. Thesoftware and/or computer program product can be implemented in theenvironment of FIG. 38. For the purposes of this description, acomputer-usable or computer readable medium can be any apparatus thatcan contain, store, communicate, propagate, or transport the program foruse by or in connection with the instruction execution system,apparatus, or device. The medium can be an electronic, magnetic,optical, electromagnetic, infrared, or semiconductor system (orapparatus or device) or a propagation medium. Examples of acomputer-readable storage medium include a semiconductor or solid statememory, magnetic tape, a removable computer diskette, a random accessmemory (RAM), a read-only memory (ROM), a rigid magnetic disk and anoptical disk. Current examples of optical disks include compactdisk—read only memory (CD-ROM), compact disc—read/write (CD-R/W) andDVD.

Although the present specification describes components and functionsthat may be implemented in particular embodiments with reference toparticular standards and protocols, the disclosure is not limited tosuch standards and protocols. Such standards are periodically supersededby faster or more efficient equivalents having essentially the samefunctions. Accordingly, replacement standards and protocols having thesame or similar functions are considered equivalents thereof.

The illustrations of the embodiments described herein are intended toprovide a general understanding of the various embodiments. Theillustrations are not intended to serve as a complete description of allof the elements and features of apparatus and systems that utilize thestructures or methods described herein. Many other embodiments may beapparent to those of skill in the art upon reviewing the disclosure.Other embodiments may be utilized and derived from the disclosure, suchthat structural and logical substitutions and changes may be madewithout departing from the scope of the disclosure. Additionally, theillustrations are merely representational and may not be drawn to scale.Certain proportions within the illustrations may be exaggerated, whileother proportions may be minimized. Accordingly, the disclosure and thefigures are to be regarded as illustrative rather than restrictive.

Accordingly, the present disclosure provides various systems, servers,methods, media, and programs. Although the disclosure has been describedwith reference to several exemplary embodiments, it is understood thatthe words that have been used are words of description and illustration,rather than words of limitation. Changes may be made within the purviewof the appended claims, as presently stated and as amended, withoutdeparting from the scope and spirit of the disclosure in its aspects.Although the disclosure has been described with reference to particularmaterials and embodiments, embodiments of the invention are not intendedto be limited to the particulars disclosed; rather the invention extendsto all functionally equivalent structures, methods, and uses such as arewithin the scope of the appended claims.

While the computer-readable medium may be described as a single medium,the term “computer-readable medium” includes a single medium or multiplemedia, such as a centralized or distributed database, and/or associatedcaches and servers that store one or more sets of instructions. The term“computer-readable medium” shall also include any medium that is capableof storing, encoding or carrying a set of instructions for execution bya processor or that cause a computer system to perform any one or moreof the embodiments disclosed herein.

The computer-readable medium may comprise a non-transitorycomputer-readable medium or media and/or comprise a transitorycomputer-readable medium or media. In a particular non-limiting,exemplary embodiment, the computer-readable medium can include asolid-state memory such as a memory card or other package that housesone or more non-volatile read-only memories. Further, thecomputer-readable medium can be a random access memory or other volatilere-writable memory. Additionally, the computer-readable medium caninclude a magneto-optical or optical medium, such as a disk or tapes orother storage device to capture carrier wave signals such as a signalcommunicated over a transmission medium. Accordingly, the disclosure isconsidered to include any computer-readable medium or other equivalentsand successor media, in which data or instructions may be stored.

Although the present application describes specific embodiments whichmay be implemented as code segments in computer-readable media, it is tobe understood that dedicated hardware implementations, such asapplication specific integrated circuits, programmable logic arrays andother hardware devices, can be constructed to implement one or more ofthe embodiments described herein. Applications that may include thevarious embodiments set forth herein may broadly include a variety ofelectronic and computer systems. Accordingly, the present applicationmay encompass software, firmware, and hardware implementations, orcombinations thereof.

Although the present specification describes components and functionsthat may be implemented in particular embodiments with reference toparticular standards and protocols, the disclosure is not limited tosuch standards and protocols. Such standards are periodically supersededby faster or more efficient equivalents having essentially the samefunctions. Accordingly, replacement standards and protocols having thesame or similar functions are considered equivalents thereof.

The illustrations of the embodiments described herein are intended toprovide a general understanding of the various embodiments. Theillustrations are not intended to serve as a complete description of allof the elements and features of apparatus and systems that utilize thestructures or methods described herein. Many other embodiments may beapparent to those of skill in the art upon reviewing the disclosure.Other embodiments may be utilized and derived from the disclosure, suchthat structural and logical substitutions and changes may be madewithout departing from the scope of the disclosure. Additionally, theillustrations are merely representational and may not be drawn to scale.Certain proportions within the illustrations may be exaggerated, whileother proportions may be minimized. Accordingly, the disclosure and thefigures are to be regarded as illustrative rather than restrictive.

One or more embodiments of the disclosure may be referred to herein,individually and/or collectively, by the term “invention” merely forconvenience and without intending to voluntarily limit the scope of thisapplication to any particular invention or inventive concept. Moreover,although specific embodiments have been illustrated and describedherein, it should be appreciated that any subsequent arrangementdesigned to achieve the same or similar purpose may be substituted forthe specific embodiments shown. This disclosure is intended to cover anyand all subsequent adaptations or variations of various embodiments.Combinations of the above embodiments, and other embodiments notspecifically described herein, will be apparent to those of skill in theart upon reviewing the description.

The Abstract of the Disclosure is provided to comply with 37 C.F.R.§1.72(b) and is submitted with the understanding that it will not beused to interpret or limit the scope or meaning of the claims. Inaddition, in the foregoing Detailed Description, various features may begrouped together or described in a single embodiment for the purpose ofstreamlining the disclosure. This disclosure is not to be interpreted asreflecting an intention that the claimed embodiments require morefeatures than are expressly recited in each claim. Rather, as thefollowing claims reflect, inventive subject matter may be directed toless than all of the features of any of the disclosed embodiments. Thus,the following claims are incorporated into the Detailed Description,with each claim standing on its own as defining separately claimedsubject matter.

The above disclosed subject matter is to be considered illustrative, andnot restrictive, and the appended claims are intended to cover all suchmodifications, enhancements, and other embodiments which fall within thetrue spirit and scope of the present disclosure. Thus, to the maximumextent allowed by law, the scope of the present disclosure is to bedetermined by the broadest permissible interpretation of the followingclaims and their equivalents, and shall not be restricted or limited bythe foregoing detailed description.

Accordingly, the novel architecture is intended to embrace all suchalterations, modifications and variations that fall within the spiritand scope of the appended claims. Furthermore, to the extent that theterm “includes” is used in either the detailed description or theclaims, such term is intended to be inclusive in a manner similar to theterm “comprising” as “comprising” is interpreted when employed as atransitional word in a claim.

While the invention has been described with reference to specificembodiments, those skilled in the art will understand that variouschanges may be made and equivalents may be substituted for elementsthereof without departing from the true spirit and scope of theinvention. While exemplary embodiments are described above, it is notintended that these embodiments describe all possible forms of theinvention. Rather, the words used in the specification are words ofdescription rather than limitation, and it is understood that variouschanges may be made without departing from the spirit and scope of thedisclosure. In addition, modifications may be made without departingfrom the essential teachings of the invention. Furthermore, the featuresof various implementing embodiments may be combined to form furtherembodiments of the invention.

1. An axial compressor comprising: a housing; a plurality of stagesarranged within the housing and along an airflow direction, each stageof the plurality of stages comprising a first blade assembly and asecond blade assembly, wherein the first blade assembly is a rotor, eachrotor in each first blade assembly being drivable independently from therotors in the other first blade assemblies.
 2. The axial compressoraccording to claim 1, further comprising an electric motor attached toeach rotor.
 3. The axial compressor according to claim 2, furthercomprising a central shaft about which the rotors rotate, wherein eachelectric motor is mounted to the central shaft.
 4. The axial compressoraccording to claim 2, wherein each electric motor is mounted to aninside of the housing.
 5. The axial compressor according to claim 1,further comprising a sensor configured to detect an airflow condition,wherein each rotor is independently drivable in accordance with thedetected airflow condition.
 6. The axial compressor according to claim1, wherein the second blade assembly is a counter-rotating rotorconfigured to rotate in an opposite rotational direction of the rotors,each counter-rotating rotor being drivable independently from the othercounter-rotating rotor and rotors.
 7. The axial compressor according toclaim 6, further comprising an electric motor attached to each rotor andcounter-rotating rotor.
 8. The axial compressor according to claim 7,further comprising a central shaft about which the rotors andcounter-rotating rotors rotate, wherein each electric motor is mountedto the central shaft.
 9. The axial compressor according to claim 7,wherein each electric motor is mounted to an inside of the housing. 10.The axial compressor according to claim 7, further comprising a sensorconfigured to detect an airflow condition, wherein each rotor andcounter-rotating rotor is independently drivable in accordance with thedetected airflow condition.
 11. The axial compressor according to claim1, further comprising a vehicle, the front end to which the compressoris mounted.
 12. The axial compressor according to claim 11, furthercomprising a tube through which the vehicle is configured to travel. 13.An axial compressor comprising: a housing; a plurality of stagesarranged within the housing and along an airflow direction, each stageof the plurality of stages comprising a rotor and a counter-rotatingrotor, each counter-rotating rotor being driveable independently fromthe counter-rotating rotors in the other stages.
 14. The axialcompressor according to claim 13, further comprising a vehicle, thefront end to which the compressor is mounted.
 15. The axial compressoraccording to claim 14, further comprising a tube through which thevehicle is configured to travel.
 16. A method for operating an axialcompressor having a plurality of stages arranged within a compressorhousing and along an airflow direction, each stage of the plurality ofstages having a first blade assembly and a second blade assembly, themethod comprising: detecting, via a sensor, an airflow condition of theaxial compressor; and driving, via an electric motor, at least one ofthe first blade assemblies and second blade assemblies independently, inaccordance with the detected airflow condition.
 17. The method accordingto claim 16, wherein the compressor is mounted to a front end of avehicle.
 18. The method according to claim 17, further comprisingoperating the vehicle to travel within a tube.
 19. An axial compressorsystem comprising: a central axial compressor; and a first plurality ofaxial compressors arranged about a longitudinal axis of the centralaxial compressor.
 20. The axial compressor according to claim 19,wherein the first plurality of axial compressors are arranged downstreamof the central axial compressor.
 21. The axial compressor according toclaim 19, further comprising a second plurality of axial compressorsarranged about the first plurality of axial compressors.
 22. The axialcompressor according to claim 19, wherein the second plurality of axialcompressors are arranged downstream of the first plurality of axialcompressors.
 23. The axial compressor according to claim 19, wherein thesecond plurality of axial compressors are staggered in thecircumferential direction with respect to the first plurality of axialcompressors.
 24. The axial compressor according to claim 17, whereineach axial compressor of the first plurality of axial compressors andcentral axial compressor are drivable independently from the other axialcompressors.
 25. The axial compressor according to claim 19, furthercomprising a vehicle, the front end to which the compressor is mounted.26. The axial compressor according to claim 25, further comprising atube through which the vehicle is configured to travel. 27-28.(canceled)